Altered expression of cruzipain and a cathepsin B-like target in a Trypanosoma cruzi cell line displaying resistance to synthetic inhibitors of cysteine-proteinases

Altered expression of cruzipain and a cathepsin B-like target in a Trypanosoma cruzi cell line displaying resistance to synthetic inhibitors of cysteine-proteinases

Autor Yong, V Google Scholar
Schmitz, V Google Scholar
Vannier-Santos, M. A. Google Scholar
Lima, APCD Google Scholar
Lalmanach, G. Google Scholar
Juliano, L. Google Scholar
Gauthier, F. Google Scholar
Scharfstein, J. Google Scholar
Instituição Universidade Federal do Rio de Janeiro (UFRJ)
Univ Tours
Universidade Federal de São Paulo (UNIFESP)
Resumo The therapeutic potential of synthetic inhibitors to the major cysteine-proteinase from Trypanosoma cruzi (cruzain or cruzipain) was recently demonstrated in animal models of Chagas' disease. A possible limitation of this strategy would be the emergence of parasite populations developing resistance to cysteine-proteinase inhibitors. Here, we describe the properties of a phenotypically stable T. cruzi cell line (R-Dm28) that displays increased resistance to Z-(SBz)Cys-Phe-CHN2, an irreversible cysteine-proteinase inhibitor which preferentially inactivates cathepsin L-like enzymes. Isolated from axenic cultures of the parental cells (IC50 1.5 mu M), R-Dm28 epimastigotes exhibited 13-fold (IC50 20 mu M) higher resistance to this inhibitor and did not display cross-resistance to unrelated trypanocidal drugs, such as benznidazol and nifurtimox, Western blotting (with mAb, affinity labeling (with biotin-LVG-CHN2) and FAGS analysis of R-Dm28 log-phase epimastigotes revealed that the cruzipain target was expressed at lower levels, as compared with Dm28c. Interestingly, this deficit was paralleled by increased expression of an unrelated Mr 30 000 cysteine-proteinase whose activity was somewhat refractory to inhibition by Z-(SBz)Cys-Phe-CHN2. N-terminal sequencing of the affinity-purified biotin-LVG-proteinase complex allowed its identification as a cathepsin B-like enzyme. Increased antigenic deposits of this proteinase were found in the grossly enlarged and electron dense reservosomes from R-Dm28 epimastigotes. Our data suggest that R-Dm28 resistance to toxic effects induced by the synthetic inhibitor may result from decreased availability of the most sensitive cysteine-proteinase target, cruzipain. the deficit in metabolic functions otherwise mediated by this cathepsin L-like proteinase is likely compensated by increased expression accumulation of a cathepsin B-like tar-get. (C) 2109 Elsevier Science B.V. All rights reserved.
Palavra-chave cruzipain
cysteine-proteinase
Chagas disease
Trypanosoma cruzi
drug resistance
Idioma Inglês
Data de publicação 2000-06-01
Publicado em Molecular and Biochemical Parasitology. Amsterdam: Elsevier B.V., v. 109, n. 1, p. 47-59, 2000.
ISSN 0166-6851 (Sherpa/Romeo, fator de impacto)
Publicador Elsevier B.V.
Extensão 47-59
Fonte http://dx.doi.org/10.1016/S0166-6851(00)00237-1
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000088035400005
Endereço permanente http://repositorio.unifesp.br/handle/11600/26320

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